        <div class="topnav">
          <ul>
            <li class="page_item page-item-1 <?php if($menu_activo == "1") echo "current_page_item"; ?>"><a href="factura.php?env=g" title="Nueva Factura de clientes"><span>Nuevo</span></a></li>
            <li class="page_item page-item-2 <?php if($menu_activo == "2") echo "current_page_item"; ?>"><a href="factura.php?env=m" title="Mostrar Ultima Factura generada"><span>Mostrar</span></a></li>
            <li class="page_item page-item-6"></li>
          </ul>
        </div>